Cross groove-type constant-velocity universal joint

Abstract

A cross groove-type constant-velocity universal joint includes an inner ring ( 10 ) having an outer circumferential surface on which ball grooves ( 12 a, 12 b ) tilted in mutually opposite directions with respect to an axial line are alternately formed in a circumferential direction; an outer ring ( 20 ) having an inner circumferential surface on which ball grooves ( 22 a, 22 b ) tilted in mutually opposite directions with respect to the axial line are alternately formed in the circumferential direction; a ball ( 30 ) received in an intersection of a pair of the ball groove ( 12 a, 12 b ) of the inner ring ( 10 ) and the ball groove ( 22 a, 22 b ) of the outer ring ( 20 ); and a cage ( 40 ) interposed between the inner ring ( 10 ) and the outer ring ( 20 ) to retain the ball ( 30 ) on the same plane. The maximum diameter of the outer circumferential surface of the inner ring ( 10 ) is greater than the minimum diameter the inner circumferential surface of the cage ( 40 ). On both end portions in the direction of width of the outer circumferential surface of the inner ring ( 10 ), spherical portions ( 16 a, 16 b ) which have the centers of curvature at the positions offset by a predetermined distance across the center of width of the inner ring ( 10 ) are provided. Furthermore, the inner circumferential surface of the cage ( 40 ) is provided with a cylindrical portion ( 44 ) at a central portion in the direction of width, and spherical portions ( 46 a, 46 b ) provided at both end portions, the spherical portions having the centers of curvature at the positions offset outwardly by a predetermined distance from the center of width of the cage ( 40 ).

1 . A cross groove-type constant-velocity universal joint comprising: an inner ring having an outer circumferential surface on which ball grooves tilted in mutually opposite directions with respect to an axial line are formed alternately in the circumferential direction; an outer ring having an inner circumferential surface on which ball grooves tilted in mutually opposite directions with respect to the axial line are formed alternately in the circumferential direction; a ball incorporated in an intersection of a pair of the ball groove of the inner ring and the ball groove of the outer ring; and a cage interposed between the inner ring and the outer ring to retain the ball on a same plane, wherein: a maximum diameter of the outer circumferential surface of the inner ring is greater than a minimum diameter of the inner circumferential surface of the cage; both end portions of the outer circumferential surface of the inner ring in a direction of width are provided with spherical portions which have a center of curvature at positions offset by a predetermined distance across the center of width of the inner ring; and the inner circumferential surface of the cage is provided with a cylindrical portion at a central portion in the direction of width and spherical portions at both end portions, the spherical portions having a center of curvature at positions offset outwardly by a predetermined distance from the center of width of the cage. 
     
     
         2 . A cross groove-type constant-velocity universal joint according to  claim 1 , wherein the number of balls is 10. 
     
     
         3 . A cross groove-type constant-velocity universal joint according to  claim 1 , wherein the number of balls is 8. 
     
     
         4 . A cross groove-type constant-velocity universal joint according to  claim 1 , wherein the number of balls is 6. 
     
     
         5 . A cross groove-type constant-velocity universal joint according to  claim 2 , wherein an intersection angle of the ball groove is 4° to 10°. 
     
     
         6 . A cross groove-type constant-velocity universal joint according to  claim 3 , wherein an intersection angle of the ball groove is 6° to 15°. 
     
     
         7 . A cross groove-type constant-velocity universal joint according to  claim 4 , wherein an intersection angle of the ball groove is 8° to 20°. 
     
     
         8 . A cross groove-type constant-velocity universal joint according to any one of  claims 1  to  7   claim 1 , used for a propeller shaft of an automobile. 
     
     
         9 . A cross groove-type constant-velocity universal joint according to any one of  claims 1  to  7   claim 1 , used for a drive shaft of an automobile. 
     
     
         10 . A cross groove-type constant-velocity universal joint according to  claim 2 , used for a propeller shaft of an automobile. 
     
     
         11 . A cross groove-type constant-velocity universal joint according to  claim 3 , used for a propeller shaft of an automobile. 
     
     
         12 . A cross groove-type constant-velocity universal joint according to  claim 4 , used for a propeller shaft of an automobile. 
     
     
         13 . A cross groove-type constant-velocity universal joint according to  claim 5 , used for a propeller shaft of an automobile. 
     
     
         14 . A cross groove-type constant-velocity universal joint according to  claim 6 , used for a propeller shaft of an automobile. 
     
     
         15 . A cross groove-type constant-velocity universal joint according to  claim 7 , used for a propeller shaft of an automobile. 
     
     
         16 . A cross groove-type constant-velocity universal joint according to  claim 2 , used for a drive shaft of an automobile. 
     
     
         17 . A cross groove-type constant-velocity universal joint according to  claim 3 , used for a drive shaft of an automobile. 
     
     
         18 . A cross groove-type constant-velocity universal joint according to  claim 4 , used for a drive shaft of an automobile. 
     
     
         19 . A cross groove-type constant-velocity universal joint according to  claim 5 , used for a drive shaft of an automobile. 
     
     
         20 . A cross groove-type constant-velocity universal joint according to  claim 6 , used for a drive shaft of an automobile.